In the related art, in the case of working a product by a machine tool including a numerical control apparatus, a CAD drawing is first made which represents the shape of a work product which is an objective. A user determines a working step from the CAD drawing and makes working program manually or using automatic programming apparatus. The user inputs the working program into the machine tool including a numerical control apparatus and mounts a non-worked work to be worked on the machine tool manually or using work automatic exchanging apparatus. Moreover, the user performs setting of the pre-set for the tool used and the tool offset amount, and mounts the tool used on a tool magazine of the machine tool. Thereafter, by executing the working program, the work is worked and the product is manufactured. In order to automate this as much as possible and reflect the knowhow accumulated by the user in the working, various inventions have been made.
In the related art, as a technique for creating the working program in which uncut portion or the like is not generated, the following is suggested.
That is, as a first technique of the related art (a method of setting cutter trajectory), there is a proposal that a working target location modeled by a plurality of line segments, and a cutting region of a cutter by a preliminary trajectory overlap with each other, and the trajectory of the cutter is corrected so that all of the line segments are included in the cutting region of the cutter, thereby creating the working programming in which uncut portion is not generated (see Patent Document 1).
Furthermore, as a second related art (a control apparatus of the machine tool), there is a proposal that a boundary portion of the worked region be made to automatically overlap with an adjacent worked region and the tool is smoothly retracted from the overlap portion, thereby preventing a level difference at the boundary portion (see Patent Document 2).
Furthermore, as a third related art (a working method, a program writing apparatus therefor, and a working device), there is a proposal that, by moving the tool from a retracted position separated on the surface of the work in the adjacent region by a predetermined distance along a path facing a working start position of the working program where a non-worked portion of the work working target region is worked, the level difference generated on the working surface of the work is made gentle, and the working surface is smoothly continued (see Patent Document 3).